Electroluminescent tube beacon



e 4, 3 A. L. BRANDT. SR 1,746,024

' I ELECTROLUMINESCENT TUBE BEACON Filed March 25, 1929 Patented Feb. 4,1930 UNITED STATES PATENT OFFICE ALFRED L. BRANDT, SR., OF BUFFALO, NEWYORK, ASSIGNOR TO FLEXLUME CORPO- RATION, OF TONAWANDA, NEW YORK, A.CORPORATION OF NEW YORK ELECTROLUMINESCENT TUBE BEACON Application filedMarch 25, 1929. Serial No. 849,587.

This invention relates to improvements in electroluminescent or neontube constructions proposing a construction which is particularly usefulas a beacon in airports and the like.

The use of neon or other electroluminescent tubes as beacons isparticularly desirable in airports due, among other things, to thefogpenetrating powers of the light emanating from the tubes. In order toincrease the amount of the light, it has been proposed to increase thediameter of the tubes. While this may be easily accomplished, it has theobjections of necessitating a special transformer to accommodate theincreased current requirement and of increasing the number of tubebreakdowns due to the heat evolved within the tube as a result of theincreased current.

Furthermore, with a tube of increased diameter, the brilliancy of lightis decreased with- I in practical current values.

The principal object of this invention is to eliminate the need of tubesof increased diameter together with their attendant objections.

A further object is to secure increased brilliancy of light by aconstruction involving a neon tube of ordinary or standard diameter andcurrent capacity.

A still further object is to provide a simple sturdy construction whichmay be readily cleaned.

An embodiment of the invention is illustrated in the accompanyingdrawings, where- Figure 1 is a plan view of the construction.

Figure 2 is a section along line 2-2 of Fig. 1.

In accordance with my invention, the display portion of anelectroluminescent tube 1 is formed with a series of closely spacedconvolutions 2. These convolutions may be of any suitable form butpreferably are made in the form of a spiral, the spirals preferablybeing of uniform diameter. While this tube may be of various diameters,a tube of rela:

tively small diameter, as compared with ordinary or standard diameters,is preferred. A

tube of this form, when illuminated and viewed from a distance, appearsas a single broad band of light having the same effect as a single tubeof a diameter equal to the diameter of the spirals but of considerablygreater brilliance. I The breadth of this band of light may be, andpreferably is, increased by the provision of one or more mirrorsextending adjacent to the tube. In the construction shown, two mirrors 3and 4 are utilized, these being placed at either side of the tube andsupported in any suitable manner.

The spirally formed tube 1 has a pronounced measure of flexibility and,in accordance with the invention, is enclosed within, and supported by,a substantially rigid glass cylinder 5. The opposite ends of the cylinder 5 preferably are joined to the walls of the tube 1 therebypreventing the access of dirt to the spiral portion 2 of, the tube whilethe intermediate portion of the cylinder preferably engages the spiralportion 2 at various points along its length tosupport the same.Obviously, to clean the tube it is only necessary to clean the outerwalls of the cylinder which may be readily accomplished. Furthermore,the cylinder 5 affords the necessary rigidity of the structurenotwithstanding the flexibility of the spiral portion 2.

In constructions where the use of the mirrors 3 and 4 is not desired ornecessary, the brilliancy of the tube may be increased by providing therear half of the cylinder 5 with a mirrored coating. While such coatingmight be placed on the outer surface of the cylinder 5, it preferablywould be placed on the inner side of the cylinder where it would beprotected against dirt and the elements. Instead of a coating, strictlyso-called, a bright plate of metal might be used and secured to eitherthe outer or inner face of the.

2. A construction of the class described,

comprisin an electroluminescent tube hav-' ing a disp a, portionarranged in the form of a spiral an a substantially rigid sleeveenclosing said spiral portion and engaging the same to support it atpoints along'its length.

In testimony whereof I aflix my signature.

ALFRED L. BRANDT, SR.

